R47 RPN Calculator & Explorer

A Reverse Polish Notation calculator isn't just a tool for getting answers like a traditional exam calculator—it's a way of thinking. It mirrors how you naturally break problems into steps, making it more like an extension of your mind than a shortcut.

A full HP-style scientific calculator — with no ads or tracking.

47 Calculator is a programmable Reverse Polish Notation scientific calculator. Trigonometry, logarithms, statistics, probability, finance, complex numbers, base conversions, matrix operations, numerical solvers — the full 47-series instruction set, in your pocket.

Free includes the calculator, a program editor for reading and writing 47-series programs, reference documentation, and a full tutorial library — probability and statistics, finance, numerical methods, programming patterns, advanced Reverse Polish Notation techniques.

The Pro version adds the Explorer — browse every menu, flag, mode, and operation the engine supports, searchable and cross-linked.

Works fully offline after first launch. Light and dark themes. No ads, no third-party analytics, no tracking, no account required.